Colorado wildlife officials partnered with Denver Water to save trout during a reservoir maintenance project

Trout rescue as water disappears

A quiet Colorado reservoir became the center of a major fish rescue after Denver Water began lowering Antero Reservoir as part of its drought response. Colorado Parks and Wildlife and Denver Water worked to prevent fish loss while the water was moved downstream.

At Antero Reservoir, trout were at risk as the planned drawdown continued. Crews used electrofishing to collect more than 1,000 trout and relocate them to nearby waters, turning the effort into a coordinated response to protect fish during a difficult drought year.

Drought puts pressure on water supply

Colorado’s 2025–26 snowpack created serious water supply concerns for Denver Water. The utility reported that streamflow forecasts called for runoff levels of only 10% to 40% of normal in 2026, while reservoir storage stayed below average.

Antero Reservoir became part of the response because it loses water quickly to evaporation. Denver Water moved water downstream to Cheesman Reservoir to preserve more of its supply while Colorado Parks and Wildlife worked to reduce fish loss.

Water redirected to Cheesman Reservoir

To reduce losses, water from Antero Reservoir was moved downstream into Cheesman Reservoir. Denver Water said the move was part of its drought response and was designed to preserve more stored water during a difficult supply year.

Officials estimated that keeping the water in Antero could allow about 5,000 acre-feet, or roughly 25% of the reservoir’s storage capacity, to evaporate. Moving it to Cheesman helped Denver Water make better use of supplies during historically low snowpack and runoff conditions.

Wildlife agency steps in early

Colorado Parks and Wildlife acted early once plans to lower the reservoir were approved. Biologists prepared a strategy to remove fish before water levels dropped too far.

Their goal was simple and urgent, save as many healthy trout as possible. Working ahead of time allowed crews to organize equipment, plan safe handling, and reduce stress on the fish during capture and relocation.

Electrofishing helps capture trout

Teams used a method called electrofishing to collect trout from Antero Reservoir. This technique uses an electric field to temporarily stun fish so biologists can net them and move them.

When performed correctly, electrofishing rarely injures fish, and stunned fish usually recover quickly. CPW aquatic biologists and Denver Water staff used the method to salvage more than 1,000 trout during the Antero drawdown.

Little-known fact: Electrofishing uses a pulser that emits an electric field to temporarily stun fish.

Thousands of fish moved safely

More than 1,000 trout were salvaged, with 981 relocated to Eleven Mile Reservoir and the remainder released into the South Fork South Platte River. Each fish was handled carefully to increase its chance of survival after relocation.

Denver Water staff worked alongside wildlife teams to transport the fish. The effort ensured that most of the rescued trout could continue living in nearby water systems instead of being lost due to drying conditions.

Trout species carefully protected

The rescued fish included rainbow trout, brown trout, cutthroat trout, and hybrid trout species. These trout are valued by Colorado anglers and were moved so they could remain in nearby waters instead of being lost during the drawdown.

Colorado Parks and Wildlife said 981 trout were relocated to Eleven Mile Reservoir, while the remaining fish were released into the South Fork South Platte River. The move kept the fish within the South Platte River basin.

Evaporation drives water decisions

Officials noted that Antero Reservoir has the highest evaporation-to-storage ratio of any Denver Water reservoir. Because Antero is shallow with a wide surface area, water stored there is more vulnerable to evaporation.

By moving water to Cheesman Reservoir, Denver Water aimed to prevent about 5,000 acre-feet of water from evaporating. That amount equals about 25% of Antero Reservoir’s storage capacity.

Little-known fact: In climates where the humidity is low and the temperatures are hot, an evaporative cooler can lower the air temperature by 20 degrees F. while it increases humidity.

Anglers join emergency effort

Local anglers played a supporting role during the emergency public fish salvage. Colorado Parks and Wildlife lifted all bag and possession limits for all fish species through sunset on May 13, before Denver Water closed public access to the property.

The public effort allowed anglers to harvest fish before the reservoir drawdown created a greater risk of loss. CPW aquatic biologists and Denver Water staff later used electrofishing to relocate more than 1,000 trout to nearby waters.

Strong teamwork behind rescue

The operation required close coordination between wildlife experts and water managers. Scheduling, transport, and fish handling all had to be carefully timed.

Regular communication helped avoid delays and ensured fish were moved quickly. The shared effort between agencies showed how cooperation can protect natural resources even during challenging environmental conditions.

Fish moved within same basin

Most relocated trout were transferred to Eleven Mile Reservoir to keep them within the South Platte River basin. Colorado Parks and Wildlife said 981 trout were moved there, while the remaining fish were released into the South Fork South Platte River.

Keeping the fish in the same basin allowed the rescued trout to remain in nearby waters connected to the broader South Platte system. It also kept many of the fish available for future angling opportunities.

Future stocking plans ahead

Once water levels recover, stocking operations at Antero Reservoir are expected to restart. This will help rebuild fish populations for future seasons.

Wildlife managers plan to monitor conditions closely before reintroducing fish. The goal is to ensure the habitat is strong enough to support healthy growth and long-term sustainability.

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A recovery story in progress

The rescue effort shows how quickly nature and water systems can change during drought years. It also highlights how fast action can protect wildlife in uncertain conditions.

With cooperation between agencies and local communities, thousands of trout were given a second chance. As water management continues to adapt, similar efforts may help protect ecosystems across the region in the future.

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What do you think about this kind of large-scale fish rescue during drought conditions? Let us know in the comments, and don’t forget to leave a like.

This slideshow was made with AI assistance and human editing.

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